Roofing underlayment

ABSTRACT

A roofing underlayment that resists water ingress around fasteners that are used to secure the underlayment to a substrate, such as a roof deck, is provided. The roofing underlayment includes a base layer, a coating layer applied to the base layer, and a water-swellable composition. An upper surface of the roofing underlayment may have a water contact angle of at least 120°.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims priority to and the benefit of U.S. Provisional Application No. 62/861,509, filed Jun. 14, 2019, the entire content of which is incorporated by reference herein.

FIELD

The general inventive concepts relate to underlayments and, more particularly, to a roofing underlayment that resists water ingress around fasteners that are used to secure the roofing underlayment to a substrate, such as a roof deck.

BACKGROUND

Underlayments are commonly used in roofing applications along with an overlayment roofing material, such as asphalt shingles, slate tiles, wooden shakes, metal roofing, and so forth. The underlayment is generally secured to the roof deck using fasteners such as nails or staples, and the overlayment roofing material is installed over the underlayment using fasteners (typically nails) that penetrate the underlayment and the roof deck. The fasteners that penetrate the underlayment create holes through the underlayment that are susceptible to water ingress.

SUMMARY

The general inventive concepts relate to a roofing underlayment that resists water ingress around fasteners that are used to secure the roofing underlayment to a substrate, such as a roof deck. To illustrate various aspects of the general inventive concepts, several exemplary embodiments of the roofing underlayment are disclosed.

In one exemplary embodiment, a roofing underlayment includes a base layer and a coating layer applied to the base layer. At least one of the base layer and the coating layer include a water-swellable composition. When the roofing underlayment is punctured by a fastener used to secure the underlayment to a substrate, the water-swellable composition expands upon coming into contact with water to form a seal around a portion of the fastener.

In one exemplary embodiment, a roofing underlayment includes a base layer, a coating layer applied to the base layer, and a layer comprising a water-swellable composition. The layer comprising the water-swellable composition may be applied to the base layer, the coating layer, or both the base layer and the coating layer. When the roofing underlayment is punctured by a fastener used to secure the underlayment to a substrate, the water-swellable composition expands upon coming into contact with water to form a seal around a portion of the fastener.

In one exemplary embodiment, a roofing underlayment includes a base layer and a coating layer applied to the base layer. An upper surface of the roofing underlayment has a water contact angle of at least 120°. Such a water contact angle renders the upper surface of the roofing underlayment resistant to wetting such that water coming into contact with the upper surface of the roofing underlayment will bead up, making it more difficult for water to infiltrate around fasteners that are used to secure the roofing underlayment.

Other aspects, advantages, and features of the general inventive concepts will become apparent to those skilled in the art from the following detailed description, when read in light of the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

The general inventive concepts, as well as embodiments and advantages thereof, are described below in greater detail, by way of example, with reference to the drawings in which:

FIG. 1 is a cross-sectional view of an embodiment of a roofing underlayment according to the present disclosure;

FIG. 2 is a cross-sectional view of an embodiment of a roofing underlayment according to the present disclosure;

FIG. 3 is a cross-sectional view of an embodiment of a roofing underlayment according to the present disclosure;

FIG. 4 is a cross-sectional view of an embodiment of a roofing underlayment according to the present disclosure; and

FIG. 5 is a cross-sectional view of an embodiment of a roofing underlayment according to the present disclosure.

DETAILED DESCRIPTION

While the general inventive concepts are susceptible of embodiment in many different forms, there are shown in the drawings, and will be described herein in detail, specific embodiments thereof with the understanding that the present disclosure is to be considered as an exemplification of the principles of the general inventive concepts. Accordingly, the general inventive concepts are not intended to be limited to the specific embodiments illustrated herein.

The general inventive concepts relate to roofing underlayments configured to resist water ingress around fasteners that are used to secure the roofing underlayment to a substrate, such as a roof deck. As will be described in further detail below, the resistance to water ingress may be accomplished by incorporating a water-swellable composition into the roofing underlayment and/or by providing a roofing underlayment with an upper surface that has a water contact angle of at least 120°.

In one exemplary embodiment, a roofing underlayment 100 is provided. Referring to FIG. 1, the roofing underlayment 100 comprises a base layer 10 and a coating layer 20 applied to a top side of the base layer 10 (i.e., a side intended to be furthest from the roof deck). Although FIG. 1 illustrates the roofing underlayment 100 having the coating layer 20 applied to the top side of the base layer 10, it is contemplated that the coating layer 20 may be applied to the bottom side of the base layer 10 instead. In another embodiment, as seen in FIG. 2, the roofing underlayment 100 comprises a base layer 10, a first coating layer 20 applied to a top side of the base layer 10, and a second coating layer 30 applied to a bottom side of the base layer 10.

In accordance with the present disclosure, the roofing underlayment 100 also comprises a water-swellable composition. The water-swellable composition may be included in one layer or multiple (e.g., two, three, four) layers of the roofing underlayment 100. By including a water-swellable composition, the roofing underlayment 100 resists water ingress through holes created by fasteners used to secure the roofing underlayment 100 to a substrate, such as a roof deck. For example, when the roofing underlayment 100 is punctured by fasteners (e.g., nails, staples), the water-swellable composition expands upon coming into contact with water to form a seal around a portion of the fastener and thereby resists water from passing through the holes created by the fasteners.

In certain embodiments, the roofing underlayment is a self-adhered underlayment. In such embodiments, a layer of adhesive material (not shown) (e.g., an asphalt-based adhesive) is applied to a bottom surface of the roofing underlayment, and the layer of adhesive material adheres the roofing underlayment to a substrate, such as a roof deck. The layer of adhesive material may be covered with a conventional release material. Fasteners are not required to secure the self-adhered roofing underlayment to the substrate. However, the water-swellable composition in the self-adhered roofing underlayment will function to resist water ingress through holes created by fasteners used to secure an overlayment roofing material (e.g., shingles, tiles, shakes) to the substrate. In other words, when the self-adhered roofing underlayment is punctured by fasteners (e.g., nails, staples) used to secure an overlayment roofing material to a roof deck, the water-swellable composition in the self-adhered roofing underlayment will expand upon coming into contact with water/moisture to form a seal around a portion of the fastener and thereby resist water from passing through the holes created by the fasteners.

The water-swellable composition of the present disclosure may comprise a variety of materials. Exemplary materials suitable for use as the water-swellable composition of the present disclosure include, but are not limited to, a bentonite, a polyacrylic acid or a salt thereof, a polyethylene oxide, a polyacrylamide, a crosslinked polyacrylate, a crosslinked polyacrylamide, a polyacrylamide copolymer, an ethylene maleic anhydride copolymer, a cross-linked carboxymethylcellulose, a polyvinyl alcohol copolymer, a starch grafted copolymer of polyacrylonitrile, a hydrolyzed cellulose-polyacrylonitrile, a polyurethane, a hydrophilic swelling rubber, and combinations thereof. In certain embodiments, the water-swellable composition of the present disclosure is at least one of sodium bentonite, sodium polyacrylate, and polyethylene oxide. In certain embodiments, the water-swellable composition of the present disclosure is sodium bentonite.

In certain embodiments, the base layer 10 comprises a water-swellable composition. The base layer 10 of the present disclosure may be formed from a variety of materials, most typically a polymeric material. Exemplary materials suitable for forming the base layer 10 of the present disclosure include, but are not limited to, a polyolefin (e.g., polyethylene, polypropylene), a polyester, a polystyrene, a polyamide, an ethylene-acrylic copolymer, a polyvinyl chloride, a polyvinylidene chloride, an ionomer resin, and combinations thereof. In certain embodiments, the base layer 10 comprises a polyolefin and a water-swellable composition. In certain embodiments, the base layer 10 comprises polypropylene, polyethylene, and combinations thereof, and a water-swellable composition comprising sodium bentonite, sodium polyacrylate, and combinations thereof.

In certain embodiments, the base layer 10 comprises up to 20% by weight of a water-swellable composition. In certain embodiments, the base layer 10 comprises from 0.1% by weight to 20% by weight of a water-swellable composition, including from 0.1% by weight to 15% by weight, from 0.1% by weight to 10% by weight, from 0.1% by weight to 5% by weight, and also including from 0.5% by weight to 2% by weight of a water-swellable composition. In certain embodiments, the base layer 10 comprises from 80% by weight to 99.9% by weight of a polymeric material selected from a polyolefin (e.g., polyethylene, polypropylene), a polyester, a polystyrene, a polyamide, an ethylene-acrylic copolymer, a polyvinyl chloride, a polyvinylidene chloride, an ionomer resin, and combinations thereof; and from 0.1% by weight to 20% by weight of a water-swellable composition. In certain other embodiments, the base layer 10 comprises from 85% by weight to 99.9% by weight of a polymeric material selected from a polyolefin (e.g., polyethylene, polypropylene), a polyester, a polystyrene, a polyamide, an ethylene-acrylic copolymer, a polyvinyl chloride, a polyvinylidene chloride, an ionomer resin, and combinations thereof; and from 0.1% by weight to 15% by weight of a water-swellable composition. In yet other embodiments, the base layer 10 comprises from 90% by weight to 99.9% by weight of a polymeric material selected from a polyolefin (e.g., polyethylene, polypropylene), a polyester, a polystyrene, a polyamide, an ethylene-acrylic copolymer, a polyvinyl chloride, a polyvinylidene chloride, an ionomer resin, and combinations thereof; and from 0.1% by weight to 10% by weight of a water-swellable composition. In still other embodiments, the base layer 10 comprises from 95% by weight to 99.9% by weight of a polymeric material selected from a polyolefin (e.g., polyethylene, polypropylene), a polyester, a polystyrene, a polyamide, an ethylene-acrylic copolymer, a polyvinyl chloride, a polyvinylidene chloride, an ionomer resin, and combinations thereof; and from 0.1% by weight to 5% by weight of a water-swellable composition. In yet other embodiments, the base layer 10 comprises a polymeric material selected from a polyolefin (e.g., polyethylene, polypropylene), a polyester, a polystyrene, a polyamide, an ethylene-acrylic copolymer, a polyvinyl chloride, a polyvinylidene chloride, an ionomer resin, and combinations thereof; and does not include a water-swellable composition. In any of the foregoing embodiments, the polymeric material may comprise polypropylene, polyethylene, and combinations thereof; and the water-swellable composition may comprise sodium bentonite, sodium polyacrylate, and combinations thereof.

The base layer 10 may be structured in a variety of ways. For example, the base layer 10 may be a woven material, a nonwoven material, or a film material. In general, and regardless of form, the base layer 10 has a basis weight of 50 g/m² to 150 g/m², including a basis weight of 75 g/m² to 125 g/m², and also including a basis weight of 80 g/m² to 105 g/m².

In certain embodiments, the base layer 10 is a woven material. In certain embodiments, the base layer 10 is a woven material comprising a polymeric material selected from a polyolefin (e.g., polyethylene, polypropylene), a polyester, a polystyrene, a polyamide, an ethylene-acrylic copolymer, a polyvinyl chloride, a polyvinylidene chloride, an ionomer resin, and combinations thereof; and a water-swellable composition. In certain other embodiments, the base layer 10 is a woven material comprising a polymeric material selected from a polyolefin (e.g., polyethylene, polypropylene), a polyester, a polystyrene, a polyamide, an ethylene-acrylic copolymer, a polyvinyl chloride, a polyvinylidene chloride, an ionomer resin, and combinations thereof; and does not include a water-swellable composition. In any of the foregoing embodiments, the polymeric material may comprise polypropylene, polyethylene, and combinations thereof; and the water-swellable composition may comprise sodium bentonite, sodium polyacrylate, and combinations thereof.

In certain embodiments, the base layer 10 is a nonwoven material. In certain embodiments, the base layer 10 is a nonwoven material comprising a polymeric material selected from a polyolefin (e.g., polyethylene, polypropylene), a polyester, a polystyrene, a polyamide, an ethylene-acrylic copolymer, a polyvinyl chloride, a polyvinylidene chloride, an ionomer resin, and combinations thereof; and a water-swellable composition. In certain other embodiments, the base layer 10 is a nonwoven material comprising a polymeric material selected from a polyolefin (e.g., polyethylene, polypropylene), a polyester, a polystyrene, a polyamide, an ethylene-acrylic copolymer, a polyvinyl chloride, a polyvinylidene chloride, an ionomer resin, and combinations thereof; and does not include a water-swellable composition. In any of the foregoing embodiments, the polymeric material may comprise polypropylene, polyethylene, and combinations thereof; and the water-swellable composition may comprise sodium bentonite, sodium polyacrylate, and combinations thereof.

In certain embodiments, the base layer 10 is a film material. In certain embodiments, the base layer 10 is a film material comprising a polymeric material selected from a polyolefin (e.g., polyethylene, polypropylene), a polyester, a polystyrene, a polyamide, an ethylene-acrylic copolymer, a polyvinyl chloride, a polyvinylidene chloride, an ionomer resin, and combinations thereof; and a water-swellable composition. In certain other embodiments, the base layer 10 is a film material comprising a polymeric material selected from a polyolefin (e.g., polyethylene, polypropylene), a polyester, a polystyrene, a polyamide, an ethylene-acrylic copolymer, a polyvinyl chloride, a polyvinylidene chloride, an ionomer resin, and combinations thereof; and does not include a water-swellable composition. In any of the foregoing embodiments, the polymeric material may comprise polypropylene, polyethylene, and combinations thereof; and the water-swellable composition may comprise sodium bentonite, sodium polyacrylate, and combinations thereof.

In certain embodiments, at least one coating layer (e.g., the first coating layer 20, the second coating layer 30, or both) comprises a water-swellable composition. The at least one coating layer 20, 30 of the present disclosure is generally water impermeable and may be formed from a variety of materials, most typically a polymeric material. Exemplary materials suitable for forming the coating layer 20, 30 of the present disclosure include, but are not limited to, a polyolefin (e.g., polyethylene, polypropylene), a polyester, a polystyrene, a polyamide, an ethylene-acrylic copolymer, a polyvinyl chloride, a polyvinylidene chloride, an ionomer resin, and combinations thereof. In certain embodiments, the at least one coating layer 20, 30 comprises a polyolefin and a water-swellable composition. In certain embodiments, the at least one coating layer 20, 30 comprises polypropylene, polyethylene, and combinations thereof; and a water-swellable composition comprising sodium bentonite, sodium polyacrylate, and combinations thereof.

In certain embodiments, the at least one coating layer 20, 30 comprises up to 20% by weight of a water-swellable composition. In certain embodiments, the at least one coating layer 20, 30 comprises from 0.1% by weight to 20% by weight of a water-swellable composition, including from 0.1% by weight to 15% by weight, from 0.1% by weight to 10% by weight, from 0.1% by weight to 5% by weight, and also including from 0.5% by weight to 2% by weight of a water-swellable composition. In certain embodiments, the at least one coating layer 20, 30 comprises from 80% by weight to 99.9% by weight of a polymeric material selected from a polyolefin (e.g., polyethylene, polypropylene), a polyester, a polystyrene, a polyamide, an ethylene-acrylic copolymer, a polyvinyl chloride, a polyvinylidene chloride, an ionomer resin, and combinations thereof; and from 0.1% by weight to 20% by weight of a water-swellable composition. In certain other embodiments, the at least one coating layer 20, 30 comprises from 85% by weight to 99.9% by weight of a polymeric material selected from a polyolefin (e.g., polyethylene, polypropylene), a polyester, a polystyrene, a polyamide, an ethylene-acrylic copolymer, a polyvinyl chloride, a polyvinylidene chloride, an ionomer resin, and combinations thereof; and from 0.1% by weight to 15% by weight of a water-swellable composition. In yet other embodiments, the at least one coating layer 20, 30 comprises from 90% by weight to 99.9% by weight of a polymeric material selected from a polyolefin (e.g., polyethylene, polypropylene), a polyester, a polystyrene, a polyamide, an ethylene-acrylic copolymer, a polyvinyl chloride, a polyvinylidene chloride, an ionomer resin, and combinations thereof; and from 0.1% by weight to 10% by weight of a water-swellable composition. In still other embodiments, the at least one coating layer 20, 30 comprises from 95% by weight to 99.9% by weight of a polymeric material selected from a polyolefin, a polystyrene, a polyamide, an ethylene-acrylic copolymer, and combinations thereof; and from 0.1% by weight to 5% by weight of a water-swellable composition. In yet other embodiments, the at least one coating layer 20, 30 comprises a polymeric material selected from a polyolefin (e.g., polyethylene, polypropylene), a polyester, a polystyrene, a polyamide, an ethylene-acrylic copolymer, a polyvinyl chloride, a polyvinylidene chloride, an ionomer resin, and combinations thereof; and does not include a water-swellable composition. In any of the foregoing embodiments, the polymeric material may comprise polypropylene, polyethylene, and combinations thereof; and the water-swellable composition may comprise sodium bentonite, sodium polyacrylate, and combinations thereof.

The at least one coating layer 20, 30 is preferably structured as a film material. In general, the at least one coating layer 20, 30 has a basis weight of 15 g/m² to 50 g/m², including a basis weight of 15 g/m² to 40 g/m², and also including a basis weight of 20 g/m² to 30 g/m². In certain embodiments, when the roofing underlayment 100 includes a first coating layer 20 and a second coating layer 30, as seen in FIG. 2, the basis weight and the material used to form the first coating layer 20 and the second coating layer 30 may be the same. In certain embodiments, when the roofing underlayment 100 includes a first coating layer 20 and a second coating layer 30, as seen in FIG. 2, the basis weight and the material used to form the first coating layer 20 and the second coating layer 30 may be different.

In certain embodiments, the at least one coating layer 20, 30 is a film material. In certain embodiments, the at least one coating layer 20, 30 is a film material comprising a polymeric material selected from a polyolefin (e.g., polyethylene, polypropylene), a polyester, a polystyrene, a polyamide, an ethylene-acrylic copolymer, a polyvinyl chloride, a polyvinylidene chloride, an ionomer resin, and combinations thereof; and a water-swellable composition. In certain other embodiments, the at least one coating layer 20, 30 is a film material comprising a polymeric material selected from a polyolefin (e.g., polyethylene, polypropylene), a polyester, a polystyrene, a polyamide, an ethylene-acrylic copolymer, a polyvinyl chloride, a polyvinylidene chloride, an ionomer resin, and combinations thereof; and does not include a water-swellable composition. In any of the foregoing embodiments, the polymeric material may comprise polypropylene, polyethylene, and combinations thereof; and the water-swellable composition may comprise sodium bentonite, sodium polyacrylate, and combinations thereof.

With reference now to FIG. 3, an exemplary embodiment of a roofing underlayment 100 a according to the present disclosure is illustrated. As seen in FIG. 3, the roofing underlayment 100 a comprises a base layer 10 a, a water-swellable layer 40 a applied to a top side of the base layer 10 a, a first coating layer 20 a applied to the water-swellable layer 40 a, and a second coating layer 30 a applied to a bottom side of the base layer 10 a. Alternatively, the water-swellable layer 40 a may be applied to a bottom side of the base layer 10 a, or both the top side and the bottom side of the base layer 10 a. Although, FIG. 3 illustrates the roofing underlayment 100 a including a first coating layer 20 a and a second coating layer 30 a,it is contemplated that either the first coating layer 20 a or the second coating layer 30 a may be omitted.

The base layer 10 a of the roofing underlayment 100 a may comprise any of the previously described structures, materials, and properties disclosed herein with respect to the base layer 10 of the roofing underlayment 100 shown in FIGS. 1 and 2. In certain embodiments, the base layer 10 a is a woven material comprising a polymeric material selected from a polyolefin (e.g., polyethylene, polypropylene), a polyester, a polystyrene, a polyamide, an ethylene-acrylic copolymer, a polyvinyl chloride, a polyvinylidene chloride, an ionomer resin, and combinations thereof. In certain embodiments, the base layer 10 a is a woven material comprising polypropylene, polyethylene, and combinations thereof. In certain embodiments, the base layer 10 a is a woven material consisting essentially of polypropylene, polyethylene, and combinations thereof. In certain embodiments, the base layer 10 a has a basis weight of 50 g/m² to 150 g/m², including a basis weight of 75 g/m² to 125 g/m², and also including a basis weight of 80 g/m² to 105 g/m².

The first and second coating layers 20a, 30 a may comprise any of the previously described structures, materials, and properties disclosed herein with respect to the coating layers 20, 30 of the roofing underlayment 100 shown in FIGS. 1 and 2. In certain embodiments, the first and second coating layers 20 a, 30 a are a film material comprising a polymeric material selected from a polyolefin (e.g., polyethylene, polypropylene), a polyester, a polystyrene, a polyamide, an ethylene-acrylic copolymer, a polyvinyl chloride, a polyvinylidene chloride, an ionomer resin, and combinations thereof. In certain embodiments, the first and second coating layers 20 a, 30 a are a film material comprising polypropylene, polyethylene, and combinations thereof. In certain embodiments, the first and second coating layers 20 a, 30 a are a film material consisting essentially of polypropylene, polyethylene, and combinations thereof. In certain embodiments, the first and second coating layers 20 a, 30 a may have a basis weight of 15 g/m² to 50 g/m², including a basis weight of 15 g/m² to 40 g/m², and also including a basis weight of 20 g/m² to 30 g/m². In certain embodiments, when the roofing underlayment 100 a includes a first coating layer 20 a and a second coating layer 30 a, as seen in FIG. 3, the basis weight and the material used to form the first coating layer 20 a and the second coating layer 30 a may be the same. In certain other embodiments, when the roofing underlayment 100 a includes a first coating layer 20 a and a second coating layer 30 a, as seen in FIG. 3, the basis weight and the material used to form the first coating layer 20 a and the second coating layer 30 a may be different.

As mentioned above, the exemplary roofing underlayment 100 a illustrated in FIG. 3 includes a water-swellable layer 40 a. In general, the water-swellable layer 40 a comprises a water-swellable composition. The water-swellable layer 40 a may have a basis weight of 15 g/m² to 40 g/m², including a basis weight of 20 g/m² to 35 g/m², and also including a basis weight of 25 g/m² to 30 g/m². By including a water-swellable layer 40 a,the roofing underlayment 100 a is able to resist water ingress through holes created by fasteners used to secure the roofing underlayment 100 a to a substrate, such as a roof deck. For example, when the roofing underlayment 100 a,including the water-swellable layer 40 a,is punctured by fasteners (e.g., nails, staples), the water-swellable composition in the water-swellable layer 40 a expands upon coming into contact with water to form a seal around a portion of the fastener and thereby resists water from passing through the holes created by the fasteners.

In certain embodiments, the water-swellable layer 40 a consists essentially of a water-swellable composition. In certain embodiments, the water-swellable layer 40 a comprises a water-swellable composition and a polymeric carrier material. Any of the previously described water-swellable compositions may be used to form the water-swellable layer 40 a. Exemplary polymeric carrier materials suitable for use in the water-swellable layer 40 a include, but are not limited to, a polyolefin (e.g., polyethylene, polypropylene), a polyester, a polystyrene, a polyamide, an ethylene-acrylic copolymer, a polyvinyl chloride, a polyvinylidene chloride, an ionomer resin, and combinations thereof. In certain embodiments, the water-swellable layer 40 a comprises sodium bentonite, sodium polyacrylate, and combinations thereof as the water-swellable composition; and polypropylene, polyethylene, and combinations thereof as the polymeric carrier material.

In certain embodiments, the water-swellable layer 40 a comprises from 20% by weight to 80% by weight of a polymeric carrier material selected from a polyolefin (e.g., polyethylene, polypropylene), a polyester, a polystyrene, a polyamide, an ethylene-acrylic copolymer, a polyvinyl chloride, a polyvinylidene chloride, an ionomer resin, and combinations thereof; and from 20% by weight to 80% by weight of a water-swellable composition. In certain other embodiments, the water-swellable layer 40 a comprises from 20% by weight to 75% by weight of a polymeric material selected from a polyolefin (e.g., polyethylene, polypropylene), a polyester, a polystyrene, a polyamide, an ethylene-acrylic copolymer, a polyvinyl chloride, a polyvinylidene chloride, an ionomer resin, and combinations thereof; and from 25% by weight to 80% by weight of a water-swellable composition. In yet other embodiments, the water-swellable layer 40 a comprises from 25% by weight to 70% by weight of a polymeric carrier material selected from a polyolefin (e.g., polyethylene, polypropylene), a polyester, a polystyrene, a polyamide, an ethylene-acrylic copolymer, a polyvinyl chloride, a polyvinylidene chloride, an ionomer resin, and combinations thereof; and from 30% by weight to 75% by weight of a water-swellable composition. In still other embodiments, the water-swellable layer 40 a comprises from 35% by weight to 60% by weight of a polymeric carrier material selected from a polyolefin (e.g., polyethylene, polypropylene), a polyester, a polystyrene, a polyamide, an ethylene-acrylic copolymer, a polyvinyl chloride, a polyvinylidene chloride, an ionomer resin, and combinations thereof; and from 40% by weight to 65% by weight of a water-swellable composition. In yet other embodiments, the water-swellable layer 40 a comprises from 45% by weight to 55% by weight of a polymeric carrier material selected from a polyolefin (e.g., polyethylene, polypropylene), a polyester, a polystyrene, a polyamide, an ethylene-acrylic copolymer, a polyvinyl chloride, a polyvinylidene chloride, an ionomer resin, and combinations thereof; and from 45% by weight to 55% by weight of a water-swellable composition. In still other embodiments, the water-swellable layer 40 a comprises from 20% by weight to 30% by weight of a polymeric carrier material selected from a polyolefin (e.g., polyethylene, polypropylene), a polyester, a polystyrene, a polyamide, an ethylene-acrylic copolymer, a polyvinyl chloride, a polyvinylidene chloride, an ionomer resin, and combinations thereof; and from 70% by weight to 80% by weight of a water-swellable composition. In any of the foregoing embodiments, the polymeric carrier material may comprise polypropylene, polyethylene, and combinations thereof; and the water-swellable composition may comprise sodium bentonite, sodium polyacrylate, and combinations thereof.

With reference now to FIG. 4, an exemplary embodiment of a roofing underlayment 100 b according to the present disclosure is illustrated. As seen in FIG. 4, the roofing underlayment 100 b comprises a base layer 10 b, a first coating layer 20 b applied to a top side of the base layer 10 b, a second coating layer 30 b applied to a bottom side of the base layer 10 b, and a water-swellable layer 40 b applied to the first coating layer 20 b, thus forming an upper surface of the roofing underlayment 100 b. Alternatively, or additionally, the water-swellable layer 40 b may be applied to the second coating layer 30 b, thus forming a lower surface of the roofing underlayment 100 b. In contrast to the exemplary embodiment of the roofing underlayment 100 a illustrated in FIG. 3, the exemplary embodiment of the roofing underlayment 100 b of FIG. 4 includes the water-swellable layer 40 b as an exterior layer of the roofing underlayment 100 b as opposed to an interior layer as seen in FIG. 3. However, it is contemplated that the roofing underlayment 100 b may include a water-swellable layer 40 b as an exterior layer of the roofing underlayment 100 b; and a water-swellable layer 40 b as an interior layer of the roofing underlayment 100 b. Furthermore, it is contemplated that the exterior water-swellable layer 40 b and the interior water-swellable layer 40 b may each be the same or different.

In one exemplary embodiment, a roofing underlayment 100 c is provided. Referring to FIG. 5, the roofing underlayment 100 c comprises a base layer 10 c and a coating layer 20 c applied to a top side of the base layer 10 c. An upper surface 50 c of the roofing underlayment 100 c is structured to have a water contact angle of at least 120°. By structuring the upper surface 50 c to have a water contact angle of at least 120°, the upper surface 50 c of the roofing underlayment 100 c resists wetting such that water coming into contact with the upper surface 50 c of the roofing underlayment 100 c will bead up, making it more difficult for water to infiltrate around fasteners that are used to either secure the roofing underlayment 100 c to a substrate or to secure an overlayment roofing material to a substrate, such as a roof deck. It should be understood that any of the previously described embodiments of the roofing underlayment may have an upper surface that is structured to have a water contact angle of at least 120°.

Achieving a water contact angle of at least 120° may be accomplished by reducing the surface energy through the use of a surfactant layer on the upper surface 50 c of the roofing underlayment 100 c and/or imparting nanoscale and/or microscale surface roughness or texture to the upper surface 50 c of the roofing underlayment 100 c. Suitable surfactants for forming the surfactant layer include, but are not limited to, silanes (e.g., fluoroalkylsilanes, polysilazanes), stearic acid compounds, and fluoropolymers. The nanoscale and/or microscale roughness or texture may be attained by applying or otherwise providing nanostructures and/or microstructures on the upper surface 50 c of the roofing underlayment 100 c. Accordingly, in certain embodiments, the upper surface 50 c of the roofing underlayment 100 c comprises a surfactant layer and/or nanostructures, microstructures, and combinations thereof.

In certain embodiments, the upper surface 50 c of the roofing underlayment 100 c comprises nanostructures. The nanostructures may be formed on the upper surface 50 c of the roofing underlayment 100 c in a variety of ways. In certain embodiments, the nanostructures are formed on the upper surface 50 c of the roofing underlayment 100 c by at least one of inorganic nanoparticles, carbon nanoparticles, and etching the upper surface 50 c of the roofing underlayment 100 c.

In certain embodiments, the upper surface 50 c of the roofing underlayment 100 c comprises nanostructures formed by inorganic nanoparticles. A variety of inorganic nanoparticles may be used to form the nanostructures on the upper surface 50 c of the roofing underlayment 100 c. Exemplary inorganic nanoparticles suitable for forming the nanostructures include, but are not limited to, silica, alumina, titania, zirconia, ceria, zinc oxide, iron oxide, vanadia, antimony oxide, and tin oxide. The inorganic nanoparticles generally have an average particle size of 10 nm to 900 nm. In certain embodiments, the inorganic nanoparticles have an average particle size of 25 nm to 750 nm, including from 30 nm to 700 nm, from 40 nm to 650 nm, from 50 nm to 600 nm, from 75 nm to 500 nm, and also including from 25 nm to 150 nm.

In certain embodiments, an inorganic nanoparticle suspension is utilized to form the nanostructures on the upper surface 50 c of the roofing underlayment 100 c. The inorganic nanoparticle suspension may comprise any one or more of the inorganic nanoparticles described herein. In addition, the inorganic nanoparticle suspension may comprise various carrier mediums to suspend the inorganic nanoparticles. Exemplary carrier mediums include, but are not limited to, water, acetone, alcohol (e.g., methanol, ethanol), hydrocarbons (e.g., pentane, hexane), fluoropolymers (e.g., polyvinylidene fluoride), polysiloxanes (e.g., polydimethylsiloxane), silanes (e.g., 1H,1H,2H,2H-perfluorooctyltriethoxysilane), and combinations thereof. In certain embodiments, the nanostructures may be formed on the upper surface 50 c of the roofing underlayment 100 c by applying the inorganic nanoparticles using a blade coating process, a squeeze coating process, a brush coating process, a spin coating process, a dip coating process, or a spray coating process.

In certain embodiments, the upper surface 50 c of the roofing underlayment 100 c comprises nanostructures formed by carbon nanoparticles (e.g., carbon black, carbon nanotubes, carbon nanofibers, carbon nanocarpets). The carbon nanoparticles generally have an average particle size of 10 nm to 900 nm. In certain embodiments, the carbon nanoparticles have an average particle size of 25 nm to 750 nm, including from 30 nm to 700 nm, from 40 nm to 650 nm, from 50 nm to 600 nm, from 75 nm to 500 nm, and also including from 25 nm to 150 nm.

In certain embodiments, a carbon nanoparticle suspension is utilized to form the nanostructures on the upper surface 50 c of the roofing underlayment 100 c. The carbon nanoparticle suspension generally comprises carbon nanoparticles and a carrier medium to suspend the carbon nanoparticles. Exemplary carrier mediums include, but are not limited to, water, acetone, alcohol (e.g., methanol, ethanol), hydrocarbons (e.g., pentane, hexane), fluoropolymers (e.g., polyvinylidene fluoride), polysiloxanes (e.g., polydimethylsiloxane), silanes (e.g., 1H,1H,2H,2H-perfluorooctyltriethoxysilane), and combinations thereof. In certain embodiments, the nanostructures may be formed on the upper surface 50 c of the roofing underlayment 100 c by applying the carbon nanoparticles using a blade coating process, a squeeze coating process, a brush coating process, a spin coating process, a dip coating process, or a spray coating process.

In certain embodiments, the nanostructures are formed on the upper surface 50 c of the roofing underlayment 100 c by etching the upper surface 50 c of the roofing underlayment 100 c. In certain embodiments, the etching of the upper surface 50 c of the roofing underlayment 100 c to form the nanostructures is carried out using acid etching, plasma etching, reactive ion etching, and combinations thereof.

In certain embodiments, the upper surface 50 c of the roofing underlayment 100 c comprises microstructures. The microstructures may be formed on the upper surface 50 c of the roofing underlayment 100 c in a variety of ways. In certain embodiments, the microstructures are formed on the upper surface 50 c of the roofing underlayment 100 c by at least one of inorganic microparticles, carbon microparticles, and etching the upper surface 50 c of the roofing underlayment 100 c.

In certain embodiments, the upper surface 50 c of the roofing underlayment 100 c comprises microstructures formed by inorganic microparticles. A variety of inorganic microparticles may be used to form the microstructures on the upper surface 50 c of the roofing underlayment 100 c. Exemplary inorganic microparticles suitable for forming the microstructures include, but are not limited to, silica, alumina, titania, zirconia, ceria, zinc oxide, iron oxide, vanadia, antimony oxide, and tin oxide. The inorganic microparticles generally have an average particle size of 1 μm to 900 μm. In certain embodiments, the inorganic microparticles have an average particle size of 25 μm to 750 μm, including from 30 μm to 700 μm, from 40 μm to 650 μm, from 50 μm to 600 μm, from 75 μm to 500 μm, and also including from 25 μm to 150 μm.

In certain embodiments, an inorganic microparticle suspension is utilized to form the microstructures on the upper surface 50 c of the roofing underlayment 100 c. The inorganic microparticle suspension may comprise any one or more of the inorganic microparticles described herein. In addition, the inorganic microparticle suspension may comprise various carrier mediums to suspend the inorganic microparticles. Exemplary carrier mediums include, but are not limited to, water, acetone, alcohol (e.g., methanol, ethanol), hydrocarbons (e.g., pentane, hexane), fluoropolymers (e.g., polyvinylidene fluoride), polysiloxanes (e.g., polydimethylsiloxane), silanes (e.g., 1H,1H,2H,2H-perfluorooctyltriethoxysilane), and combinations thereof. In certain embodiments, the microstructures may be formed on the upper surface 50 c of the roofing underlayment 100 c by applying the inorganic microparticles using a blade coating process, a squeeze coating process, a brush coating process, a spin coating process, a dip coating process, or a spray coating process.

In certain embodiments, the upper surface 50 c of the roofing underlayment 100 c comprises microstructures formed by carbon microparticles. The carbon microparticles generally have an average particle size of 10 μm to 900 μm. In certain embodiments, the carbon microparticles have an average particle size of 25 μm to 750 μm, including from 30 μm to 700 μm, from 40 μm to 650 μm, from 50 μm to 600 μm, from 75 μm to 500 μm, and also including from 25 μm to 150 μm.

In certain embodiments, a carbon microparticle suspension is utilized to form the microstructures on the upper surface 50 c of the roofing underlayment 100 c. The carbon microparticle suspension generally comprises carbon microparticles and a carrier medium to suspend the carbon microparticles. Exemplary carrier mediums include, but are not limited to, water, acetone, alcohol (e.g., methanol, ethanol), hydrocarbons (e.g., pentane, hexane), fluoropolymers (e.g., polyvinylidene fluoride), polysiloxanes (e.g., polydimethylsiloxane), silanes (e.g., 1H,1H,2H,2H-perfluorooctyltriethoxysilane), and combinations thereof. In certain embodiments, the microstructures may be formed on the upper surface 50 c of the roofing underlayment 100 c by applying the carbon microparticles using a blade coating process, a squeeze coating process, a brush coating process, a spin coating process, a dip coating process, or a spray coating process.

In certain embodiments, the microstructures are formed on the upper surface 50 c of the roofing underlayment 100 c by etching the upper surface 50 c of the roofing underlayment 100 c. In certain embodiments, the etching of the upper surface 50 c of the roofing underlayment 100 c to form the microstructures is carried out using acid etching, plasma etching, reactive ion etching, and combinations thereof.

As mentioned above, the upper surface 50 c of the roofing underlayment 100 c may have a water contact angle of at least 120° by the use of a surfactant and/or the formation of at least one of nanostructures and microstructures on the upper surface 50 c. In certain embodiments, the upper surface 50 c of the roofing underlayment 100 c has a water contact angle of 120° to 180°, including a water contact angle of 130° to 180°, a water contact angle of 140° to 180°, a water contact angle of 150° to 180°, a water contact angle of 160° to 180°, and also including a water contact angle of 120° to 160°.

All references to singular characteristics or limitations of the present disclosure shall include the corresponding plural characteristic or limitation, and vice versa, unless otherwise specified or clearly implied to the contrary by the context in which the reference is made.

All combinations of method or process steps as used herein can be performed in any order, unless otherwise specified or clearly implied to the contrary by the context in which the referenced combination is made.

All ranges and parameters, including but not limited to percentages, parts, and ratios, disclosed herein are understood to encompass any and all sub-ranges assumed and subsumed therein, and every number between the endpoints. For example, a stated range of “1 to 10” should be considered to include any and all subranges between (and inclusive of) the minimum value of 1 and the maximum value of 10; that is, all subranges beginning with a minimum value of 1 or more (e.g., 1 to 6.1), and ending with a maximum value of 10 or less (e.g., 2.3 to 9.4, 3 to 8, 4 to 7), and finally to each number 1, 2, 3, 4, 5, 6, 7, 8, 9, and 10 contained within the range.

The underlayments of the present disclosure can comprise, consist of, or consist essentially of the essential elements and limitations of the disclosure as described herein, as well as any additional or optional components or limitations described herein or otherwise known to be useful in underlayment applications.

To the extent that the terms “include,” “includes,” or “including” are used in the specification or the claims, they are intended to be inclusive in a manner similar to the term “comprising” as that term is interpreted when employed as a transitional word in a claim. Furthermore, to the extent that the term “or” is employed (e.g., A or B), it is intended to mean “A or B or both A and B.” When the Applicant intends to indicate “only A or B but not both,” then the term “only A or B but not both” will be employed. Thus, use of the term “or” herein is the inclusive, and not the exclusive use. Furthermore, the phrase “at least one of A, B, and C” should be interpreted as “only A or only B or only C or any combinations thereof.” In the present disclosure, the words “a” or “an” are to be taken to include both the singular and the plural. Conversely, any reference to plural items shall, where appropriate, include the singular.

In some embodiments, it may be possible to utilize the various inventive concepts in combination with one another. Additionally, any particular element recited as relating to a particularly disclosed embodiment should be interpreted as available for use with all disclosed embodiments, unless incorporation of the particular element would be contradictory to the express terms of the embodiment. Additional advantages and modifications will be readily apparent to those skilled in the art. Therefore, the disclosure, in its broader aspects, is not limited to the specific details presented therein, the representative apparatus, or the illustrative examples shown and described. Accordingly, departures may be made from such details without departing from the spirit or scope of the general inventive concepts.

The scope of the general inventive concepts presented herein are not intended to be limited to the particular exemplary embodiments shown and described herein. From the disclosure given, those skilled in the art will not only understand the general inventive concepts and their attendant advantages, but will also find apparent various changes and modifications to the devices, systems, and methods disclosed. It is sought, therefore, to cover all such changes and modifications as fall within the spirit and scope of the general inventive concepts, as described and/or claimed herein, and any equivalents thereof. 

What is claimed is:
 1. A roofing underlayment comprising: a base layer; and a coating layer applied to the base layer, wherein at least one of the base layer and the coating layer includes a water-swellable composition.
 2. A roofing underlayment comprising: a baser layer; a coating layer applied to the base layer; and a layer comprising a water-swellable composition.
 3. The roofing underlayment according to claim 2, wherein the layer comprising the water-swellable composition is applied to the base layer.
 4. The roofing underlayment according to claim 2, wherein the layer comprising the water-swellable composition is applied to the coating layer.
 5. The roofing underlayment according to claim 1, wherein the base layer is selected from a woven material, a nonwoven material, and a film material.
 6. The roofing underlayment according to claim 1, wherein the base layer comprises at least one of a polyolefin, a polyester, a polystyrene, a polyamide, an ethylene-acrylic copolymer, a polyvinyl chloride, a polyvinylidene chloride, and an ionomer resin.
 7. The roofing underlayment according to claim 1, wherein the coating layer is a film material.
 8. The roofing underlayment according to claim 1, wherein the coating layer comprises at least one of a polyolefin, a polyester, a polystyrene, a polyamide, an ethylene-acrylic copolymer, a polyvinyl chloride, a polyvinylidene chloride, and an ionomer resin.
 9. The roofing underlayment according to claim 1, wherein the water-swellable composition comprises at least one of a bentonite, a polyacrylic acid or a salt thereof, a polyethylene oxide, a polyacrylamide, a crosslinked polyacrylate, a crosslinked polyacrylamide, a polyacrylamide copolymer, an ethylene maleic anhydride copolymer, a cross-linked carboxymethylcellulose, a polyvinyl alcohol copolymer, a starch grafted copolymer of polyacrylonitrile, a hydrolyzed cellulose-polyacrylonitrile, a polyurethane, and a hydrophilic swelling rubber.
 10. The roofing underlayment according to claims 1, wherein an upper surface of the roofing underlayment has a water contact angle of 120° to 180°.
 11. A roofing underlayment comprising: a base layer; and a coating layer applied to the base layer; wherein an upper surface of the roofing underlayment has a water contact angle of at least 120°.
 12. The roofing underlayment according to claim 11, wherein the upper surface of the roofing underlayment comprises a surfactant layer comprising at least one surfactant selected from a silane, a stearic acid compound, and a fluoropolymer.
 13. The roofing underlayment according to claim 11, wherein the upper surface of the roofing underlayment comprises at least one of nanostructures and microstructures.
 14. The roofing underlayment according to claim 13, wherein the nanostructures are formed by at least one of inorganic nanoparticles, carbon nanoparticles, and etching the upper surface of the roofing underlayment; and wherein the microstructures are formed by at least one of inorganic microparticles, carbon microparticles, and etching the upper surface of the roofing underlayment.
 15. The roofing underlayment according to claim 13, wherein the upper surface of the roofing underlayment comprises nanostructures formed by inorganic nanoparticles, wherein the inorganic nanoparticles comprise at least one of silica, alumina, titania, zirconia, ceria, zinc oxide, iron oxide, vanadia, antimony oxide, and tin oxide.
 16. The roofing underlayment according to claim 11, wherein the base layer is selected from a woven material, a nonwoven material, and a film material.
 17. The roofing underlayment according to claim 11, wherein the base layer comprises at least one of a polyolefin, a polyester, a polystyrene, a polyamide, an ethylene-acrylic copolymer, a polyvinyl chloride, a polyvinylidene chloride, and an ionomer resin.
 18. The roofing underlayment according to claim 11, wherein the coating layer is a film material.
 19. The roofing underlayment according to claim 11, wherein the coating layer comprises at least one of a polyolefin, a polyester, a polystyrene, a polyamide, an ethylene-acrylic copolymer, a polyvinyl chloride, a polyvinylidene chloride, and an ionomer resin.
 20. The roofing underlayment according to claim 11, wherein the upper surface of the roofing underlayment has a water contact angle of 120° to 180°. 